How Many Mh Units For A 5x2x2 Tank?

[xxBarneyxx]

Seriously looking at upgrading (been thinking about it for ages but it "might" actually happen in the next couple of months ). I have 2 Arcadia 4ft lumianairs which I will run in the short term but its actually going to work out cheaper to run MH (especially with the extra water depth).

Will be looking at 250w units but just wondering how many I will need for this size of tank. Would 2 be enough (assuming the bracing is in the middle of the tank)? Dont think I have ever seen any info anywhere on how much area a MH can cover. Looking at one of the setups in my LFS they have a shallow, round tank that's about 3 foot across and their 75w MH "seems" to cover the lot pretty well (obviously its probably not as bright at the edges but to the naked eye it doesn't look a lot different). Would need the 250w for the depth of tank but would ideally not like to be running more than 2 units if I can help it to save on the electric.

 

[Crazy fishes]

250W metal halide is better at 2' but you can get away with 150W. This was an issue I have recently discussed with Ski and a 150-250W MH can illuminate 2 cubic feet (2x2x2 feet) so for a five foot tank I would use 3 MH units. This is why you can get away with the 150W as you will have some overlap in the middle and 2' is where 150W halides begin to lost their usefulness. It is ultimately up to you what wattage you use because remember 250W get hotter and depending on the corals you wish to keep may inhibit growth in the shallow water region. Ski runs 2x 175W on a 36" (3 foot) aquarium and he has said that works fine. No need to waste electricity this hobby is expensive as it is.

Hope it helps

Regards

 

[xxBarneyxx]

hmmm very good point about the overlap using 3 lower wattage units, I hadnt thought about that! Taking that in to consideration I think your right and 3 150W units will be a much better option. Thanks

 

[seffieuk]

whoo hoo, a new tank to watch................... Will you run both tanks or sell the one you have now Barney?

Seffie x

 

[SkiFletch]

3x150watt would certainly be a better option for coverage, BUT if you have a center brace, you'll cast a big shadow with the middle one and it will look very unpleasing to the eye. You could of course get around this by removing the center brace and replacing it with two middle braces if you like... Depends on how deep down the DIY rabbit hole you want to go

 

[kj23502]

3x150watt would certainly be a better option for coverage, BUT if you have a center brace, you'll cast a big shadow with the middle one and it will look very unpleasing to the eye. You could of course get around this by removing the center brace and replacing it with two middle braces if you like... Depends on how deep down the DIY rabbit hole you want to go

What about taking off the brace? Are they really needed? Running into a center brace issue w/my 120g...hope you don't mind me asking Barney. This may be useful to you to maybe?!?

 

[N1z]

You will be suprised on running costs i found out my 150watt halide runs on 576watts cos its 240volts x 2.4Amps

 

[rabbut]

3x150watt would certainly be a better option for coverage, BUT if you have a center brace, you'll cast a big shadow with the middle one and it will look very unpleasing to the eye. You could of course get around this by removing the center brace and replacing it with two middle braces if you like... Depends on how deep down the DIY rabbit hole you want to go

What about taking off the brace? Are they really needed? Running into a center brace issue w/my 120g...hope you don't mind me asking Barney. This may be useful to you to maybe?!?

Depends on the glass you are using. Thick "optiwhite" (due to the required thickness) glass could be used and make it braceless, but the costs on a 5X2X2 of doing that would be phenominal You'd be looking at 4-5" thick glass (as a guess, could be on the low side... It's larger that I have the space to build in, so I've never had to quote the glass for a normal 5X2X2, let a lone a braceless one...) at least...

If you are working on any kind of reasonable budget, bracing will be required to allow you to use Float glass of reasonable thickness, to keep building costs down. Bracing is deapth, length and wideth dependant, but typically, you want one brace for every 3ft of length...

All the best
Rabbut

 

[xxBarneyxx]

thanks a lot for the input. Im going to be looking for a second hand tank ideally so will have to see what comes up. If all else fails I will get one built (think I got quoted about £400 last time I looked) so can then talk to them about the bracing and maybe work it around the lights.

 

[SkiFletch]

If a tank has a center crossbrace it absoloutely must have a replacement. You CAN clamp the tank, cut the brace out leaving little tabs of the old brace left, then replacing it with a new acrylic brace.